I am having a little trouble, and am hoping that somebody can help me. I have an 86 Ram w/ 43,000 original miles on it, and up till yesterday, I had had no trouble what so ever. I was driving along, came up to a stop sign, and my truck died. I tried to start it, and it turned over but would not start. I thought maybe I had flooded it, so I put the pedal to the floor and tried to start it again and this time it started but when I let off the gas, it coughed and sputtered and tried as hard as it could to die. By trial and error I have figured out that the truck runs fine as long as it is cold, but once it gets warmed up when you come to a stop it will die. If you put it in park or nuetral, it will run extremly rough. But if you keep giving it a little bit of gas as you are slowing down, it will stay running almost normal like. It will also surge just a bit while you are up to speed. I am not sure what the engine is, but I do know that it is Fuel Injected. I have no idea what might be going on, so any help would be gretly appritiated.

 

It's an 86 fuel injected? I'm pretty sure the 318 went fuelie in 88 and the 360 a little while later. I'm not up on my 6 cylinder history though.

I'm going to guess that there's something wrong with the choke. Either that or the ecm, but if it's fuel injected maybe the O2 sensor?

 

I was really suprised to see that it was Fuel Injected as well. Is there any way that I can test the O2 sensor on my own?.

 

I've got an '89 that has very similar symptoms whenever it gets below 1/4 tank of gas. I fill er up, when I get a good paycheck, and she does fine. However, this weekend we had the camper on it and climbed up to a mountain lake at 8,000 feet. When we got up there the thing just shut down. It was a VERY hot day, about 104º down in the valley. Pulling a heavy load, up a steep grade, with the a/c on, for awhile, till it just got too heated. Once it cooled down it was fine. I suspect it actually vapor locked. Driving home the next day it ran just fine. Even over one more mountain pass. I don't know how to make it run any cooler. I just put on a new tranny cooler and new fan clutch. Does okay until we turn on the a/c, then it still gets too hot when we're haulin the camper.

 

I have a little more info. Dad said the Injectors were a throttlebody? I don't have a clue as to what that means, but Maybe it will make sense to you guys. A friend of mine suggested that I take some carb/choke cleaner and spray onto the butterfly plates while I had the truck running. I did this and noticed a distinct improvment in the symptoms. The sides and plates were all black when I started, but when I got done they were very clean. As far as the driving goes, now instead of dieing when you come to a stop, it will run very roughly, but will not die. Again, any suggestions would be greatly appritiated.

 

Perhaps somebody swapped in a newer manifold and stuff for the TBI (throttle body injection).

TBI is a step in the right direction, as far as fuelie systems go it's about the worst since the intake manifold is still wet - meaning fuel and air, not just air goes through it. I say it's a step in the right direction because the angle isn't so much an issue as with a carb'd engine, but it's not the most efficient. Multi-port or direct injection are much better, but weren't offered for a few more years.

To test the O2 sensors you'll have to see what kind they are - I just put a wideband in my 5.0 and it's got 7 wires going to it. The OEM ones had 3 wires. I'd bet yours has either 2 oe 3 wires. 1 would be the 12 volt source, 1 would be the element ground, and 1 would be the signal wire (the black one usually). The output voltage of the black wire should be around .5 volts at idle if your mixture is right. IIRC the 3-wire sensors usually run between $50-100.

I think you might be on the right track here, if the truck is an 86 it's probably due for a fairly thorough tuneup. Cleaning the throttle body is a good move, also check the air filter, fuel filter, cap, rotor, plugs, wires, make sure you've got good grounds between the engine and chassis as well as the battery. If the TBI system uses a MAF sensor you might try inspecting that for dirt buildup - don't quote me on this but I think you can use rubbing alcohol to clean it up when it's cold. PCV valve might need to get replaced too.

As far as running cooler while going up the pass I've got 2 suggestions - 1) make sure you've got a fan shroud and that the top and sides of the radiator are more or less sealed against the grill so the air is forced through it instead of around it, and 2) invest in a pusher electric fan to mount on the front side. You could run it off a switch or a thermostat. If you want to do it right I'd remove the clutch fan and put a pair of electric fans instead, so long as you don't go mud or steam bogging in your truck. You'll pick up power and it'll be more efficient.

 

Hey, thanks for all the ideas. I'll get to work on them and let yall know how it goes. Thanks again.

 

All of my experience has been with a 79. When this was haooening to me, it was a coil getting hot and failing. The electronic ignition failed at one time also. Be sure you check the ballast resistor.

 

It sure sounds electrical, It also sounds fuel related. If it were mine I wouldstart at the fuel supply.(fuel pump) is that electrical? If it has injection than the fuel pump most likely is in the gas tank. the pump usually has a filterwith it also. Oh, it would'nt hurt to change the in line fuel filter. Hope this helps. R.V.